Causal Association of Cardiovascular Risk Factors and Lifestyle Behaviors With Peripheral Artery Disease: A Mendelian Randomization Approach.

Background We investigated the causal associations between the genetic liability to cardiovascular and lifestyle risk factors and peripheral artery disease (PAD), using a Mendelian randomization approach. Methods and Results We performed a 2-sample inverse-variance weighted Mendelian randomization analysis, multiple sensitivity analyses to assess pleiotropy and multivariate Mendelian randomization analyses to assess mediating/confounding factors. European-ancestry genomic summary data (P<5×10-8) for type 2 diabetes, lipid-fractions, smoking, alcohol and coffee consumption, physical activity, sleep, and education level were selected. Genetic associations with PAD were extracted from the Million-Veteran-Program genome-wide association studies (cases=31 307, controls=211 753, 72% European-ancestry) and the GoLEAD-SUMMIT genome-wide association studies (11 independent genome-wide association studies, European-ancestry, cases=12 086, controls=449 548). Associations were categorized as robust (Bonferroni-significant (P<0.00294), consistent over PAD-cohorts/sensitivity analyses), suggestive (P value: 0.00294-0.05, associations in 1 PAD-cohort/inconsistent sensitivity analyses) or not present. Robust evidence for genetic liability to type 2 diabetes, smoking, insomnia, and inverse associations for higher education level with PAD were found. Suggestive evidence for the genetic liability to higher low-density lipoprotein cholesterol, triglyceride-levels, alcohol consumption, and inverse associations for high-density lipoprotein cholesterol, and increased sleep duration were found. No associations were found for physical activity and coffee consumption. However, effects fully attenuated for low-density lipoprotein cholesterol and triglycerides after correcting for apoB, and for insomnia after correcting for body mass index and lipid-fractions. Nonsignificant attenuation by potential mediators was observed for education level and type 2 diabetes. Conclusions Detrimental effects of smoking and type 2 diabetes, but not of low-density lipoprotein cholesterol and triglycerides, on PAD were confirmed. Lower education level and insomnia were identified as novel risk factors for PAD; however, complete mediation for insomnia and incomplete mediation for education level by downstream risk factors was observed.

Insulin resistance as a marker for the immune-metabolic subtype of depression.

OBJECTIVE: Insulin resistance (IR), a marker of metabolic dysregulation and pro-inflammatory state, moderates the antidepressant treatment effect in patients with type 2 diabetes (T2D) and is therefore a potential marker for personalized treatment. Based on data from a light therapy trial (NTR4942), we aimed to evaluate whether 1) depression symptoms differ according to the level of IR, and 2) improvement of specific depression symptoms drive the positive effects of light therapy in those with higher IR. METHODS: This secondary analysis in 59 individuals with depression and T2D explored differences in depressive symptom profile (30-item Inventory of Depressive Symptomatology (IDS)) at baseline and in response to light therapy (versus placebo), between lower and higher IR individuals, using Likelihood Ratio tests and Linear-by-linear association. IR was measured using the gold standard, a hyperinsulinemic-euglycaemic clamp. RESULTS: At baseline, higher IR individuals reported more symptoms of irritability (p=0.024) anhedonia (no interest in people and activities: p=0.011; absence of pleasure and enjoyment: p=0.021), fatigue (fatigue: p=0.036; physical fatigue: p=0.035) and hypersomnia (p=0.029) relative to persons with lower IR, who reported more insomnia (nightly awakening: p=0.041; early morning awakening: p=0.012). Light therapy led to an improvement across IDS symptoms in higher IR individuals, while in lower IR individuals, light therapy improved early morning awakening (p=0.005) and interest in people and activities (p=0.015), but worsened mood (feeling sad: p=0.001; feeling irritable: p=0.002; interpersonal sensitivity: p=0.014). CONCLUSIONS: Results add to the hypothesis of an immune-metabolic subtype of depression, and suggest that IR might be a promising focus for precision medicine.

Vitamin D supplementation for the prevention of depression and poor physical function in older persons: the D-Vitaal study, a randomized clinical trial.

BACKGROUND: Depressive symptoms and impaired physical functioning are prevalent among older adults. Supplementation with vitamin D might improve both conditions, particularly in persons with low vitamin D status. OBJECTIVE: The D-Vitaal study primarily aimed to investigate the effect of vitamin D supplementation on depressive symptoms, functional limitations, and physical performance in a high-risk older population with low vitamin D status. Secondary aims included examining the effect of vitamin D supplementation on anxiety symptoms, cognitive functioning, mobility, handgrip strength, and health-related quality of life. METHODS: This study was a randomized placebo-controlled trial with 155 participants aged 60-80 y who had clinically relevant depressive symptoms, ≥1 functional limitations, and serum 25-hydroxyvitamin D [25(OH)D] concentrations of 15-50/70 nmol/L (depending on season). Participants received 1200 IU/d vitamin D3 (n = 77) or placebo tablets (n = 78) for 12 mo. Serum 25(OH)D was measured at baseline and 6 mo; outcomes were assessed at baseline, 6 mo, and 12 mo. Linear mixed-models analyses were conducted to assess the effect of the intervention. RESULTS: The supplementation increased serum 25(OH)D concentrations in the intervention group to a mean ± SD of 85 ± 16 nmol/L compared with 43 ± 18 nmol/L in the placebo group after 6 mo (P < 0.001). No relevant differences between the treatment groups were observed regarding depressive symptoms, functional limitations, physical performance, or any of the secondary outcomes. CONCLUSIONS: Supplementation with 1200 IU/d vitamin D for 12 mo had no effect on depressive symptoms and physical functioning in older persons with relatively low vitamin D status, clinically relevant depressive symptoms, and poor physical functioning. This trial is registered with the Netherlands Trial Register (www.trialregister.nl) under NTR3845.

Effects of Light Therapy on Mood and Insulin Sensitivity in Patients With Type 2 Diabetes and Depression: Results From a Randomized Placebo-Controlled Trial.

OBJECTIVE: Depression is common in patients with type 2 diabetes and adversely affects quality of life and diabetes outcomes. We assessed whether light therapy, an antidepressant, improves mood and insulin sensitivity in patients with depression and type 2 diabetes. RESEARCH DESIGN AND METHODS: This randomized, double-blind, placebo-controlled trial included 83 patients with depression and type 2 diabetes. The intervention comprised 4 weeks of light therapy (10,000 lux) or placebo light therapy daily at home. Primary outcomes included depressive symptoms (Inventory of Depressive Symptomatology [IDS]) and insulin sensitivity (M-value derived from the results of a hyperinsulinemic-euglycemic clamp). Secondary outcomes were related psychological and glucometabolic measures. RESULTS: Intention-to-treat analysis showed that light therapy was not superior to placebo in reducing depressive symptoms (-3.9 IDS points [95% CI -9.0 to 1.2]; P = 0.248) and had no effect on insulin sensitivity (0.15 mg/kg*min [95% CI -0.41 to 0.70]; P = 0.608). Analyses incorporating only those participants who accurately adhered to the light therapy protocol (n = 51) provided similar results, but did suggest positive effects of light therapy on depression response rates (≥50% reduction in IDS points) (26% more response; P = 0.031). Prespecified analysis showed effect moderation by baseline insulin sensitivity (P = 0.009) and use of glucose-lowering medication (P = 0.023). Light therapy did not affect depressive symptoms in participants with higher insulin sensitivity or those who use only oral glucose-lowering medication or none at all, but it did produce a relevant effect in participants with lower insulin sensitivity (-12.9 IDS points [95% CI -21.6 to -4.2]; P = 0.017) and a trend toward effectiveness in those using insulin (-12.2 IDS points [95% CI -21.3 to -3.1]; P = 0.094). Light therapy was well tolerated. CONCLUSIONS: Although this trial is essentially inconclusive, secondary analyses indicate that light therapy might be a promising treatment for depression among a subgroup of highly insulin-resistant individuals with type 2 diabetes.

Effects of Two-Year Vitamin B12 and Folic Acid Supplementation on Depressive Symptoms and Quality of Life in Older Adults with Elevated Homocysteine Concentrations: Additional Results from the B-PROOF Study, an RCT.

Lowering elevated plasma homocysteine (Hcy) concentrations by supplementing vitamin B12 and folic acid may reduce depressive symptoms and improve health-related quality of life (HR-QoL) in older adults. This study aimed to test this hypothesis in a randomized controlled trial. Participants (N = 2919, ≥65 years, Hcy concentrations ≥12 µmol/L) received either 500 µg vitamin B12 and 400 µg folic acid daily or placebo for two years. Both tablets contained 15 µg vitamin D3. Depressive symptoms were measured with the Geriatric Depression Scale-15 (GDS-15). HR-QoL was assessed with the SF-12 Mental and Physical component summary scores and the EQ-5D Index score and Visual Analogue Scale. Differences in two-year change scores were analyzed with Analysis of Covariance (ANCOVA). Hcy concentrations decreased more in the intervention group, but two-year change scores of the GDS-15 and three of four HR-QoL measures did not differ between groups. The EQ-5D Index score declined less in the intervention group than in the placebo group (mean change 0.00 vs. -0.02, p = 0.004). In conclusion, two-year supplementation with vitamin B12 and folic acid in older adults with hyperhomocysteinemia showed that lowering Hcy concentrations does not reduce depressive symptoms, but it may have a small positive effect on HR-QoL.

Health care providers' perceived barriers to and need for the implementation of a national integrated health care standard on childhood obesity in the Netherlands - a mixed methods approach.

BACKGROUND: In 2010, a national integrated health care standard for (childhood) obesity was published and disseminated in the Netherlands. The aim of this study is to gain insight into the needs of health care providers and the barriers they face in terms of implementing this integrated health care standard. METHODS: A mixed-methods approach was applied using focus groups, semi-structured, face-to-face interviews and an e-mail-based internet survey. The study's participants included: general practitioners (GPs) (focus groups); health care providers in different professions (face-to-face interviews) and health care providers, including GPs; youth health care workers; pediatricians; dieticians; psychologists and physiotherapists (survey). First, the transcripts from the focus groups were analyzed thematically. The themes identified in this process were then used to analyze the interviews. The results of the analysis of the qualitative data were used to construct the statements used in the e-mail-based internet survey. Responses to items were measured on a 5-point Likert scale and were categorized into three outcomes: 'agree' or 'important' (response categories 1 and 2), 'disagree' or 'not important'. RESULTS: Twenty-seven of the GPs that were invited (51 %) participated in four focus groups. Seven of the nine health care professionals that were invited (78 %) participated in the interviews and 222 questionnaires (17 %) were returned and included in the analysis. The following key barriers were identified with regard to the implementation of the integrated health care standard: reluctance to raise the subject; perceived lack of motivation and knowledge on the part of the parents; previous negative experiences with lifestyle programs; financial constraints and the lack of a structured multidisciplinary approach. The main needs identified were: increased knowledge and awareness on the part of both health care providers and parents/children; a social map of effective intervention; structural funding; task rearrangements; a central care coordinator and structural information feedback from the health care providers involved. CONCLUSIONS: The integrated health care standard stipulate that the care of overweight or obese children be provided using an integrated approach. The barriers and needs identified in this study can be used to define strategies to improve the implementation of the integrated health care standard pertaining to overweight and obese children in the Netherlands.

Vitamin D supplementation to prevent depression and poor physical function in older adults: Study protocol of the D-Vitaal study, a randomized placebo-controlled clinical trial.

BACKGROUND: Depressive symptoms and decreased physical functioning are interrelated conditions and common in older persons, causing significant individual and societal burden. Evidence suggests that vitamin D supplementation may be beneficial for both mental and physical functioning. However, previous randomized controlled trials have yielded inconsistent results and often had suboptimal designs. This study examines the effect of vitamin D supplementation on both depressive symptoms and physical functioning in a high-risk population of older persons with low vitamin D status. METHODS/DESIGN: The D-Vitaal study is a randomized, double-blind, placebo-controlled trial investigating the effects of a daily dose of 1200 IU vitamin D3 versus placebo for one year on depressive symptoms and physical functioning (primary outcomes) in older adults. Participants (N = 155, age 60-80 years) were recruited from the general population. Eligibility criteria included the presence of depressive symptoms, ≥1 functional limitation and serum 25-hydroxyvitamin D levels between 15 and 50/70 nmol/L (depending on season). Secondary outcomes include incidence of major depressive disorder, anxiety symptoms, health-related quality of life, cognitive function and cost-effectiveness of the intervention. DISCUSSION: With this study, we aim to elucidate the effects of vitamin D supplementation on depressive symptoms and physical functioning in older persons who are at high risk of developing more substantial mental and physical problems. If effective, vitamin D supplementation can be a preventive intervention strategy that is easy to implement in the primary care setting. TRIAL REGISTRATION: Netherlands Trial Register NTR3845. Registered 6 February 2013.